In a semiconductor manufacturing apparatus using plasma, such as a plasma etching apparatus or a plasma CVD apparatus, in the past, as a device for easily mounting and fixing a wafer to a sample stage and maintaining the temperature of the wafer at a desired temperature, an electrostatic chuck device has been used.
As such an electrostatic chuck device, for example, an electrostatic chuck device in which an electrostatic chuck portion having a plate-like electrode for electrostatic chucking embedded therein and a base portion for temperature adjustment having a coolant flow path for coolant circulation formed therein are joined and integrated together by a bonding portion is known (Patent Literature No. 1).
The bonding portion is easily corroded by radicals or the like generated during plasma treatment. For this reason, if the electrostatic chuck is used under a plasma environment for a long time, there is a case where the bonding portion is corroded.
If the bonding portion is corroded by the plasma, the adhesive strength between the electrostatic chuck portion and the base portion for temperature adjustment decreases. There is a concern that a decrease in adhesive force may result in a reduction in the life of a product, warping of a member, or the like. Further, since the heat transferability of the portion corroded by the plasma deteriorates, non-uniformity of the temperature of a wafer can be caused.
For the purpose of preventing such corrosion of the bonding portion, for example, Patent Literature No. 2 discloses an electrostatic chuck device provided with an electrostatic chuck having a concavo-convex shape on a side surface, and a ring-shaped insulation ring fitted to the concavo-convex shape and disposed on the outer periphery of the electrostatic chuck.
Further, Patent Literature No. 3 discloses a substrate placing table having a base having a recess portion and an electrostatic chuck portion which is fitted to the recess portion, in which an adhesive layer is provided on only the flat surface of a bottom portion of the recess portion.
Further, in order to avoid corrosion of a bonding portion by radicals or the like generated during plasma treatment, a substrate placing table having a base having a recess portion and an electrostatic chuck portion which is fitted to the recess portion, in which an adhesive layer is provided on only the flat surface of a bottom portion of the recess portion, has been proposed (Patent Literature No. 3).
Further, in recent years, in a plasma etching apparatus, according to finer wiring or the like of a semiconductor device, uniformity of an etching rate has been more severely required than that in the past. The etching rate by plasma etching is affected by the density of plasma, the surface temperature of a wafer, the concentration distribution of an etching gas, or the like. The plasma density or the etching gas concentration has a density or concentration distribution on the surface of the wafer, and therefore, in addition to the uniformity of the wafer surface temperature, adjustment of the in-plane temperature distribution of the wafer is required.
Therefore, an electrostatic chuck device with a heater function, in which a heater member is mounted between an electrostatic chuck portion and a base portion for temperature adjustment, has been proposed (Patent Literature No. 4).
This electrostatic chuck device with a heater function can locally create a temperature distribution in a wafer, and therefore, it is possible to appropriately set the in-plane temperature distribution of the wafer in accordance with a plasma etching rate.